Centering device



1943- A. M. KRZEGER UENTERII'EG DEEICE 2 Sheets-Sheet l Filed Dec. 11,1941 N 1 wk mwl A; M. KRIEGER CENTERING DEVICE Jan. 19, 1943.

2 Sheets-Sheet 2 Filed Dec 11, 1941 Patented Jan. 19, 1943 UNTED STATESPATENT OFFICE CENTERING DEVICE Arthur Michael Krieger, Mount Lebanon,Pa. Application December 11, 1941, Serial No. 422,599

2 Claims.

This invention relates to centering devices, and more particularly tothose which are used to center misaligned workpieces, such as successivestrips of steel, preparatory to the connecting thereof, although notlimited thereto.

,In the manufacture of strip steel, for example, it is sometimesnecessary to connect successive strips in order that they may beprocessed as a unit. Due to the fact that the strips are-heavy andthereforehard to manage, it is difficult to correctly align them.

It is an object of the present invention to center workpieces of varioustypes, and particularly relatively rigid strip metal, in an accurate andrapid manner.

Another object is the provision of apparatus capable of performing inthe foregoing manner, which is relatively easy and inexpensive tomanufacture, install, and operate.

The invention, then, comprises the features hereinafter fully describedand as particularly pointed outin the claims, the following descriptionand the annexed drawings setting forth in detail a certain illustrativeembodiment of the invention, this being indicative of one of the numberof ways in which the principles of the invention may be employed.

In said drawings:

Figure 1 is a plan of the apparatus of the present invention.

Figure 2 is a side elevation.

Figure 3 is a fragmentary plan, on an enlarged scale, illustrating adetail.

Figure 4 is an enlarged sectional view on the line IV-IV of Figure 2.

. The apparatus of the present invention is used in conjunction with acentering device which is adapted to contact the workpiece and move itinto a desired position. As a specific instance, the centering devicemay take the form of a pair of movable side guides whichare widely usedin the centering of strip steel and the like. These side guides aredisposed above and adjacent to a series of rollers over which the stripmay be fed, and are operated by motors which are suitably actuated. In amanner well known in the art. these motors are controlled by an operatorwho is in a position to determine to what extent the workpiece is to becentered.

The foregoing instrumentalities as such form no part of the presentinvention, and are therefore neither shown nor more specificallydescribed hereinafter.

In accordance with the teachings of the present invention there isprovided above, and longitudinally of the direction of movement of thestrip or other work object'a pair of spaced parallel horizontallyextending guides 2. As a specific instance, these spaced parallelhorizontally extending guides 2 may be disposed relatively adjacent themotor-operated: side guides de-' scribed hereinbefore. Disposed forsliding engagement along the upper surface of the guides 2 is a pair ofsubstantially spaced traveling nuts 4 each of which has formedintegrally therewith a dovetailed member} which rides in acomplementarily-formed recess provided by and between the said guides.Connected to and depending from the dovetailed member 5 of each of thenuts 4 is a vertical bar 1 having secured to the bottom thereof alaterally-extending plate 8. Each of the plates 8 carries a. dependingpivot pin 9'. Disposed along the bottom of each of the plates 8 is ahorizontally-extending arm l0 which is carried intermediate its ends bythe depending pivot pin 9. These arms l0 extend substantially parallelto each other and at one end thereof carry nuts and bolts collectivelydesignated at l2 for the adjustable attachment thereto of a controllever l3 which extends in substantially the same general direction.Carried on the projecting end of each of the control levers I3 is adepending member I4 which is adapted to engage the adjacent edge of thestrip or other workpiece to be centered or aligned.

Referr ng more particularly to Figure 3, each of the plates 8 has formedintegrally therewith an extension l6 which carries an adjustablesetscrew H for engaging the most adjacent side of the arm III. In viewof the fact that it is intended that the arm lil normally contact theset-screw I1. it is biased in this direction by means of a load springl8. The excessive outward movement of the arm Ill is prevented by alimit switch 20 wh ch is adjacently disposed on the plate 8 and througha suitable electrical circuit not shown) operates the reversible motor29 to move the nuts 4 further apart. The movement of the arm l0 out ofcontact with the operating arm of the said limit switch discontinues theoperation of the reversible motor 29.

According to the foregoing construction and arrangement of parts, itwill be perceived that when a strip, or other workpiece to be centeredis fed along the rollers A and beneath the guides 2. its side edges willbe engaged by the strip-engaging elements [4, and if the strip isoif-center, one of the control levers l3 will be moved in such manner asto cause the corresponding movement of the arm l against the action ofthe load spring I8.

Disposed to extend above the opening between the spaced parallel guides2, and through the traveling nuts 4 is a rotatable screw 25. Thisrotatable screw is joumaled adjacent its ends in end bearings 26, and atits center in a center bearing 21. Those portions of the screw 25 whichextend through the nuts 4 are in screw-threaded engagement therewith,one providing a righthand thread and the other providing a left-handthread. It will be perceived, too, that these screw-threaded portionsare on either side of, and evenly spaced with respect to, the centerbearing 21. Disposed adjacent one end of the guides 2 is a reversiblemotor 29 which, through a gear reduction unit 30 and suitable connectinginstrumentalities, is adapted to rotate the screw 25 in eitherdirection. This construction permits the traveling nuts 4 andaccordingly the strip-engaging elements l4 to be moved in unison towardand away from each other andin a like manner with respect to a workpiecedisposed therebetween.

.As will be seen more clearly in Figure 4, each of the depending bars 1has secured thereto a Selsyn-type transmitter 33, the shaft 34 of whichdepends vertically and carries a pinion 35. These pinions 35 are engagedby segmental gears 31 which are carried on the adjacent ends of the armsID. The transmitter cable 40 of each of the Selsyn-type transmitters 33is connected as at 42 to a conduit 43 which extends along one of theguides 2. Disposed atop the center bearing 21 for the screw 25 is aSelsyn-type differential receiver 45 which is connected through theconduit 43 with the transmitter cable 40 of both of the Selsyn-typetransmitters 33. Disposed at suitable intervals along the conduit 43 isa pair of limit switches 4'! having instrumentalities susceptible ofbeing engaged by a limit switch operating arm 48 which is carried by oneof the nuts 4. The Selsyn-type differential receiver 45 operates in theusual manner a pair of micro-type switches 46 each of which is connectedin such manner as to operate the control for one of the motors C of theside guides B.

The electrical circuits connecting the Selsyntype transmitters 33, theSelsyn-type differential receiver 45, and their associated electricalinstrumentalities, are entirely conventional and form no part of thepresent invention; and accordingly are neither shown herein nor morefully described hereinafter.

In operation:

A strip X, or other workpiece, is fed over the rollers A, between theside guides B and completely over the elevated, laterally-extendinghorizontal guides 2. When the workpiece X is moved in this manner, thenuts 4 are so disposed that the strip-engaging instrumentalities I4 arespaced with respect to the side edges of the workpiece. The movement ofthe workpiece is continued until the trailing end thereof approachesproximity to the guides 2. The movement of the workpiece X is continueduntil the trailing end thereof leaves the side guides B. Disposedbetween the side guides B and the guides 2 may be a welding machine orother connecting instrumentality (not shown). Another strip (or other'workpiece) is fed over the rollers A with its advance end disposedbetween the side guides B.

The trailing end of the first workpiece and the advance end of thesecond are thus placed in sufficiently close proximity to permit oftheir being connected together. at which time it is essential that theybe properly centered.

At this point the operator energizes the motor 29 in such manner as tomove the nuts 4 toward each other. This movement is continued. until oneof the strip edge-engaging instrumentalities I4 makes contact with theadjacent edge of the workpiece X. When one of the strip edge-engaginginstrumentalities l4 engages the edge of the strip, its movement isstopped, while there is continued the movement of the nut 4 by which itis carried. This continued movement causes the bar I, Selsyn-typetransmitter 33, and the pinion 35 of the latter, to be moved withrespect to the arm l0 carrying the segmental gear 31. This movement,then, causes the partial rotation of the shaft 34 of that particularSelsyn-type transmitter 33.

The partial rotation of the shaft 34 will be such as to cause the shaftof the Selsyn-type differential receiver 45 to rotate in the properdirection to bring about off-center correction. This rotation of theshaft of the Selsyn-type differential receiver 45 is such as to causethe operation of the proper micro-type switch 46, which in turn operatesthe motor C of the proper side guide B. More specifically, theSelsyn-type transmitters 33 and the Selsyn-type differential receiver 45are selfsynchronous devices which are similar to threephase inductionmotors but have shuttle-wound rotors with two definite poles, thewindings of which are connected through collector rings to asingle-phase, alternating-current source of excitation. The Selsyn-typetransmitters 33 are operated at the sending points as generators, andare therefore called transmitters, while the Selsyntype differentialreceiver 45 is operated at the receiving point as a motor, and istherefore known as the receiver." The energization of the proper sideguide B causes the movement of the advance end of the second strip tocorrect the offcenter condition. The operation of the said side guide Bcontinues until the second strip edgeengaging instrumentality l4 engagesthe edge of the strip, thus causing the rotation of the shaft 34 of thesecond Selsyn-type transmitter to a degree sufiicient to equalize theforce impressed on the Selsyn-type differential receiver 45 by the firstSelsyn-type transmitter. This causes the shaft of the Selsyn-typedifferential receiver 45 to reverse, returning it to the neutralposition. Upon its return to neutral position, the shaft of theSelsyn-type differential receiver 45 operates the proper micro-typeswitch 46 to deenergize the motor C of the proper side guide B. In thismanner the side guiding is stopped at the proper time, and the twostrips will be in exact longitudinal alignment.

As soon as the two strips are in proper longitudinal alignment, they maybe connected together in any suitable manner, after which the operatormay operate the motor 29 in such manner as to withdraw the nuts 4 andtheir connected strip edge-engaging instrumentalities l4. This operationof the motor 29 is continued until the outer of the limit switches 41 isoperated, at which time the motor is automatically deenergized. Theinner limit switch 41 operates to prevent excessive inward movement ofthe nuts 4.

While I have shown and described one specific embodiment of the presentinvention, it will be seen that I do not wish to be limited exactlythereto, since various modifications may be made without departing fromthe scope of the invention. as defined in the appended claims.

' I claim:

1. The combination with side guides for work- "pieces, of a centeringdevice comprising means for engaging the workpiece at different points,and

, means actuated thereby for controlling the operation of said sideguides, said .means ,including synchronous electrical motors.

2. The combination with side guides for workpieces, of a centeringdevice comprising means for engaging two opposite points of a workpiece,and means actuated thereby for controlling the operation of said sideguides, said means including synchronous electrical motors.

ARTHUR MICHAEL KRIEGER.

